Update dashmap requirement from 5.5.3 to 6.1.0 in /tests/fuzz

Updates the requirements on [dashmap](https://github.com/xacrimon/dashmap) to permit the latest version.
- [Release notes](https://github.com/xacrimon/dashmap/releases)
- [Commits](xacrimon/dashmap@v.5.5.3...v.5.5.3)

---
updated-dependencies:
- dependency-name: dashmap
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -106,7 +106,7 @@ num-integer = "0.1.46"
 ryu-js = "1.0.1"
 tap = "1.0.1"
 thiserror = "1.0.63"
-dashmap = "5.5.3"
+dashmap = "6.1.0"
 num_enum = "0.7.3"
 itertools = { version = "0.13.0", default-features = false }
 portable-atomic = "1.7.0"